Sludge digester tanks for the treatment of sewage therein have been in existence for some time. However, certain drawbacks have been noted in the equipment employed in the past and one such drawback resides in the fact that no provision has been made to insure the proper seeding of the primary sludge by mixing some of the digested sludge already in the digester tank with the incoming primary sludge.
With the above in mind it is the primary object of the invention to employ an apparatus to insure the seeding of the incoming primary sludge by mixing the same within a confined area with some of the digested sludge prior to the release of the mixture into the digester tank.
Another object of the invention is to provide a structure including an updraft tube having openings formed therein for the flow of digested sludge within the tube and to mix with the primary sludge also fed into the updraft tube prior to the release of the combined mixture into the digester tank.
Another object of the invention is to employ a suitable plastic composition in the formation of the internal parts of the digester tank so as to prevent the formation of corrosion of any of these parts of the tank.
Another object of the invention is to provide a means whereby the gases fed under pressure into the digester tank can be used as a carrier for enzymes, bacterial cultures, or chemicals employed to enhance the digestive process within the tank.
Another object of the invention is to provide a digester tank and parts therein free of any obstruction so as to insure a smooth flow of the contents therein thus avoiding any clogging within the tank which could impede the smooth flow of the sewage undergoing treatment in the tank.
Another object of the invention is to provide a suitable valving arrangement in the conduits leading into the updraft tube in the digester tank so that the amount of feed of the gases as well as the amount of primary sludge fed thereinto may be regulated.
Another object of the invention is to provide a means such as a suitable timing mechanism whereby the opening and closing of the valves in the conduits leading to the updraft tube may be effected on a time basis.
Other objects and advantages of the invention will be apparent from the following description and from the drawings.